Our study using the isotope-enabled climate model MIROC5-iso model shows that lakes may have contributed to the Green Sahara during the mid-Holocene period (6000 years ago). The lakes induced cyclonic circulation response, enhancing the near-surface monsoon westerly flow and potentially humidifying the northwestern Sahara with the stronger West African Monsoon moving northward. Our findings provide valuable insights into understanding the presence of the Green Sahara during this period.

Over recent decades, opposite trends in sea ice extent have been found between the Arctic and Antarctic. However, early Antarctic expeditions provide much information regarding sea ice. Here summer sea ice positions recorded during 1820–1843 have been compared to recent satellite observations. The key findings of this study indicate a 19th century summer northernmost sea ice latitude in much of the Weddell Sea that was further north than during the modern era.

Water isotopes, both hydrogen and oxygen, correlate with the salinity of the sea. Here we reconstruct the surface seawater isotopic composition during the last deglaciation based on the measured hydrogen isotopic composition of alkenones, organic compounds derived from haptophyte algae, and compared it to oxygen isotopes of calcite shells produced in the bottom water. Our results suggest that surface seawater experienced more freshening during the last 20 000 years than the bottom seawater.

We present two new sea surface temperature (SST) records in comparison with available SST records to reconstruct South Atlantic paleoceanographic evolution. Our results show a low SST gradient in the Eocene–early Oligocene due to the persistent gyral circulation. A higher SST gradient in the Middle–Late Miocene infers a stronger circumpolar current. The southern South Atlantic was the coldest region in the Southern Ocean and likely the main deep-water formation location in the Middle Miocene.

To quantify the sensitivity of the earth system to orbital-scale forcings, we conducted an unprecedented quasi-continuous coupled general climate model simulation with the Community Earth System Model, which covers the climatic history of the past 3 million years. This study could stimulate future transient paleo-climate model simulations and perspectives to further highlight and document the effect of anthropogenic CO₂ emissions in the broader paleo-climatic context.

We reconstruct the Intertropical Convergence Zone (ITCZ) behavior during the past 3000 years over northeastern Brazil based on oxygen stable isotopes of stalagmites. Paleoclimate changes were mainly forced by the tropical South Atlantic and tropical Pacific sea surface temperature variability. We describe an ITCZ zonal behavior active around 1100 CE and the period from 1500 to 1750 CE. The dataset also records historical droughts that affected modern human population in this area of Brazil.

Understanding of past climate change depends, in part, on how accurately we can estimate the ages of events recorded in geologic archives. Here we present a new software package, called BIGMACS, to improve age estimates for paleoclimate data from ocean sediment cores. BIGMACS creates multiproxy age estimates that reduce age uncertainty by probabilistically combining information from direct age estimates, such as radiocarbon dates, and the alignment of regional paleoclimate time series.

We simulated the climate difference between the mid-Holocene (MH) and the preindustrial (PI) periods and quantified the effects of Earth orbital parameters (ORBs) and greenhouse gases (GHGs) on the climate difference. We think the insignificant difference in the Atlantic meridional overturning circulation between the MH and PI periods has resulted from the competing effects of the ORBs and the GHGs on the climate.

Drivers for dinocyst assemblage compositions differ regionally and through time. Shifts in the assemblages can sometimes only be interpreted robustly by locally and sometimes globally calibrated transfer functions, questioning the reliability of environmental reconstructions. We suggest the necessity of a thorough evaluation of transfer function performance and significance for downcore applications to disclose the drivers for present and fossil dinocyst assemblages in a studied core location.

We investigate the Maritime Continent climate  in the mid-Piacenzian warm period and find it is warmer and wetter and the sea surface salinity is lower compared with preindustrial period. Besides, the fresh and warm water transfer through the Maritime Continent was stronger. In order to avoid undue influence from closely related models in the multimodel results, we introduce a new metric, the multi-cluster mean, which could reveal spatial signals that are not captured by the multimodel mean.